campbell



(No Model.) v 3Sheets--Sheet 1.

A. CAMPBELL.

ELEGTRIGALLY AOTUATE'D SHEET STOBFOR PRINTING P EssEs. No. 291,575. Patented Jan. 8 1884.

l N V E N TO R WITNESSES yam Wow; By his Attorneys, M M W V I N. Pncns. PhowLillmgr-xpher. Washing'an. u. c.

(1T0 Model.) 3 Sheets Sheet 2.

A. CAMPBELL. ELBOTRIGALLY ACT-HATED SHEET STOP FOR PRINTING PRESSES. No. 291,575. Patented Jan. 8, I884.

I I I I I I I I I l I I I I I I I I I I I I I F i131 5 I WITNESSESz- I Wrfi By his flttbrneys,

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N PETER'S. yhnrunh n m. Walhinglon. a. c.

(N0 Mk del. s Sheets-Sheet 3..

A. CAMPBELL.

ELEGTRIGALLY AGTUATED SHEET STOP FOR. PRINTING PRESSES. N0. 291,575. Patented Jan. 8,-1884.

' INVENTOR:

' By his Attomeys,

N. FEYERS. Pholo-Liflwgmphw. Washington. D. C.

' UNiTEn STATEs PATENT @tricn.

ANDREW CAMPBELL, or BROOKLYN, AssieNoR ro JOHN ncnouennm AND nnnulvn l\IcLOUGHLIN, or NEW YORK, N. Y.

ELECTRICALLY-ACTUATED SHEET-STOP FOR PRINTING-PRESSES.

SPECIFICATION forming part of Letters Patent No. 291,575, dated January 8, 1824, Application filed June 13,1983. (Xe mode i an Improved Electrically-Actuated Sheet- Stop for Printing-Presses, of which the following is a specification.

The object of my invention is to provide a printing press or machine with electricallyactuated means for holding down the. sheet after it hasbeen presented to the front guides, and before it has been seized by the grippers, in order that the tremor or jar of the machine may not shift it and destroy the register.

I 5 To effect this purpose, I provide two hinged fingers, mounted on opposite sides of the feedboard, and, by preference, near the end of same, adjacent to the cylinder, and arrange these to be thrown down upon the sheet by means of an electro-magnet or magnets at the proper time, so as to press the sheet down firmly upon the feed-board and prevent it from shifting until seized by the grippers. The electro-magnets are in a circuit, which is broken and closed at the proper time by the movements of some part of the press or ma chine.

In the drawings which serve to illustrate myinvention, Figure lis a side elevation of a portion of a' cylinder printing press or ma chine, illustrating the application of my improvements thereto. Figs. 2 and 3 illustrate, on a large scale, the construction of the stopfinger and its operating-magnets, the former 5 being a section on line 2 2 in Fig. 3, and the latter a section on line 3 3 in Fig. 2. Fig. 4 is a plan, on a smaller scale, somewhat in the nature of adiagram, illustrating the principle upon which my device operates, and the aro rangement of the electric circuit and other parts; and Fig. 5 is a diagram showinga modified arrangement of the circuit and circuitbreaking device.

InFig. II have shown my sheetst'op applied 4 5 to a press with swinging front guides and a lifting feed-board constructed similar to the press described in a pending application of mine; but it may as well be applied to any other form of press. In this figure, A is the cylin- 5c der; B, the feed-board, and C the time-wheel,

Closing of the grippers the jarring motion or tremor of the press is liable to move the sheet away from the front guides and out of register. To prevent this, I employ the device I will now describe with reference to Figs. 2 and 3. a

In a suitable box or case, D, mounted on the feed-board at the side, (see Fig. 4,) is placed an electro-maguet, E, the armature (l of which is attached to one arm. 0, of a bell-crank leverv fulcrumed at g. The other arm, h, of this lever extends back over the magnet, and is coupled by a link, 1', to a crank-wheel, j, which oscillates on an arbor or axis, In.

To the crank-wheelj is attached an elastic finger, Z, which plays in a slot in the front of the casing D. Then the magnet E is excited,

its armature is attracted and the fingerl is thrown down upon the sheet m, upon which 1t exerts sufficient elastic pressure to hold the sheet firmly in place until seized. circuit is broken, the retractingspring a returns the parts to the position indicated by full lines in F1 2 and releases the sheet. The dotted lines in this figure show the magnet excited and the finger thrown down upon the sheet.

I have described but one finger and its operative mechanism, but I prefer to employ two of theseone at each side of the board-as shown in Fig. 1

When the The two magnets which actuate the fingers are in an electric circuit with abattery, dynamo-machine, or other source ofelectro-motive force, F, (see Fig. 4,) and means are employed for breaking and closing said circuit'at the proper time to properly operate the fingers Z. This breaking and closing of the circuit is cffected by the moving parts of the press in any way desired; but I prefer to employ the means illustrated in Fig. 1, and which I will now describe.

On the inner face of the time-wheelO is fixed a cam, 0, which at each revolution of said wheel lifts a lever, p, hung to the main frame, and causes its free end q to contact with an elastic contact-piece, r, also fixed to the main frame. The parts q and r are in the circuit formed by the wires 1, 2, 3, and 4, the latter shown in dotted lines only in Fig. 4, itbeing under the feed-board. The circuit is closed after the sheet has been placed in position against the front guides, and is broken an instant after the grippers close down upon the sheet. This insures the retention of the sheet in place until it is fairly seized. Fig. 5 shows a slightly different arrangement of the circuit and circuit-closing device. I11 this construction the press itself form's-a part of the circuit, the circuit being closed only while cam 0 is in contact with contact-piece q.

I do not wish to limit myself to any particular form of circuit-closing device, as the number of forms that may be employed is almost infinite. It is only necessary to the successful working of my invention that the circuit shall be broken and closed by some moving part of the press, and that these breaks and closures shallbe effected at the proper time; nor do I wish to limit myself to the precise construction of the finger-actuating mechanism shown in Fig. 2, as this also is susceptible of many formal modifications. It is only necessary that the attractive power of the magnet shall be exerted to depress or throw down the finger Z. to protect it. It is obvious also that my device could be operated with anormallyclosed circuit. In this case the finger would be thrown down by a spring and upheld by the magnet.

I- contemplate employing as a motor a dynamo-machine operated in connection with the press; but a battery might be employed. I may also employ separate circuits and separate circuit-closing devices for each finger, but it is better, or as well, to employ one circuit, as shown.

It will be observed that I arrange the fingersZ to lie across the sheet m, and at right angles, substantially, to its line of movement when fed. By this arrangement the fingers are prevented from disturbing the sheet when brought down upon it, as they are actuated simultaneously and very quickly by the electric current. The older forms of sheet-holders are very liable to disturb the sheet and alter its register.

I may employ a secondary circuit-breaker The inclosing of the mechanism is only.

thatis to say, I may placethis in some rapidlymoving part of the machine-say the fly-wheel, for example. This, having acircumference of siX feet, would travel fifty-four feet to twelve feet of the cylinder-surface, so that a circuitbreaker in the time-wheel could be incontact thirty degrees, and that of the fly-wheel three hundred and fifty degrees. By this means the circuit would be closed during the interval between placing the sheet and the time of closing the fingers, except at the instant before they are absolutely in contactwith the sheet. At this instant the rapid motion of the fiywheel would break the, circuit, thereby lifting the sheet-holding electrical finger, and allow the sheet to be drawn away without any resistance. This will secure perfect uniformity in taking the sheet.

Having thus described my invention, I claim- 1. In a cylinder printing-press, the combination, with the feed-board and front guides, of a sheet-holding finger or fingers, Z, and electro magnetic means, substantially as described. for operating said finger or fingers, whereby they are caused-to press upon the sheet after it is placed against the front guides and to hold it in place until it is seized by the grippers, substantially as set forth.

2. The combination, with the feed-board and front guides of a printing-press, of the magnet E and its armature, the lever e h, link 2', crank j, spring at, and finger Z, all arranged to operate substantially as set forth.

3. The combination, in a printing press having a feed-board and front guides, of two electro-magnets mounted on the sidesof the feed-board, an electric generator to excite said magnets, circuit-wires, and a circuit breaking and closing device, substantially as described, whereby the moving parts of the press are made to break and close the circuit, stop-fingers Z, and means, substantially as described, whereby the electro-magnets are caused to actuate said fingers, all arranged substantially as and for the purposes set forth.

4. A cylinder printing-press provided with a feed-board and front guides, and with two electricallyactuated fingers, Z, arranged on IIO opposite sides of the feed-board, and in planes substantially at right angles to .the line of 

